Current airframe and fuselage structures, including wing and tail structures of commercial aircraft, are typically built from panel modules which are joined together by means of fasteners, such as rivets. In recently developed commercial aircraft, welding has also been used to join panel modules as well as to join stiffener members, such as stringers, to skin panels to construct such panel modules. Regardless of the joining technique employed, the fabrication of skin panels of an aircraft fuselage structures will usually involve joining panel modules, which comprise extensive sheet elements that form skin panels provided with structural stiffening members, such as stringers, frame or rib elements, and/or angles. The skin panels of these panel modules are then joined to form a continuous skin of the fuselage structure. Although aluminium alloys have conventionally been used and are advantageous in mechanical loading cycles (e.g. due to take-off and landings) and dynamic temperature cycles (e.g. −70° C. to 50° C.), composite materials, such as fibre-reinforced composites, are becoming more prevalent in airframe and fuselage construction.
Regardless of the material used, corrosion resistance and an aerodynamically smooth outer surface or skin of the airframe or fuselage structure is desirable, together with adequate strength under dynamic loading. The overall structure should be light-weight and the production procedures should be time-efficient and environmentally friendly to provide easy series production without excessive risk to worker health or safety from the materials involved, with easy disposal of any waste materials. Depending on the specific requirements, the design should furthermore be feasibly fail-safe, or at least damage-tolerant, and required repair solutions should be feasible via relatively simple or straight-forward techniques, e.g. that do not require overly specialized tools or equipment.